Articulator for artificial dentures



July 1952 l G. E. BJGRKLUND ,6

. ARTICULATOR FOR ARTIFICIAL DENTURES Filed Feb. 28, 1946 3 Sheets-Sheetl INVENTOR AQA'ATTORNEY July 22; 1952 V G. E. BJORKLUND 2,603,869

ARTICULATOR FOR ARTIFICIAL DENTURES Filed Feb. 28, 1946 5 Sheets-Sheet 2INVENTOR 4/ M W W/M MTTORNEY Patented July 22, 1952 mm STATES PATENTOFFICE 1 2,603,869 I Y .ARTICULATOR. FOR ARTIFICIAL DENTURES Gustaf ErikBjorklund, Stockholm, Sweden Application mamas, 1946,.SerialNo. 650,783

. .In Sweden March 5, 1945'v 7 Claims. (01; 32- 32) .In themanufacturing called, articulators are used in order to make possible anapplication of the teeth on the den? tures .whereby the chewing motionnatural to the patient. is attained. These articulators are principally.composed o f-a lower part and an upper. part which can be moved inrelation to each other. in about the same way as the lower jaw movesginrelation to the upperjaw. When the articulator is used the position ofthepatients chewing surfaces are localized in relation to the centre. ofmotion of the jaw mechanism by means of certain measuring instruments.Thereafter h Se-measurements as a base models of-the jaws "arex-formedand put into the articulator, the .upperjawmodelbeing attached to theupper part and the lower jaw model to the lower part. The articulator isprovided with such adjustin arrangements. as to enable the surgeon toadjust the same in'Such a way that the models can carryout the samemovements as, the patients jaws.

. The manufacturing of the dentures in conformity to-the models isthereafter not performed by the dentist but by a dental technician. Inorder to. carry out his work in theright way the latter neets-accesstonot only themodels but also the articulator. with the adjustments made.by the dentist; As the technicianmay have his workshiplocated at aplacefar away from the locality of artificial dentures so of..the ,.dentistsoffice it is not practical to send the whole articulator. Even if thiscould be done withoutinconvenience there "is. always the risk ofathearticulatorv'being deformed or otherwise damaged during transportationso; that the same adjustment doesnot correspond to the actual jawmotion. Because of this the technician should be provided-with .anarticulator which coincides with the dentist's articulator so, that themodels maybe moved from one articulator to the other without anydivergences arising. However it'has proved difficult tomanufacturearticulators with such Close tolerances. Even if the articulators areexactly alike when new they may be altered little by little on accountof careless usage or wear... I I

-;:The present invention has for its purpose to remedy thesedrawbacksand consists in the articulator being provided witharrangements which make it possible forthe dentist as well as thetechnician to control and adjust their articulators to such, acoincidence .thatthemodels can be moved from one, articulator to anotherwithout ,ilf ltroduciiigerrors and inaccuracies. According tothefjinvention avfirm but releasable coupling is inserted betweentheupper part' of the articii-- lator and the lower part in such a waythat the position of the upper part can be adjusted in relation to thelower part. In orderto ensure the right adjustment of the articulatorthe upper part and the lower part are locked in their cor rect relativepositions by means of a sage fixture or the like.

In the following the invention will be further described with referenceto the annexed drawings in which Fig. 1 shows an example of anarticulator constructed according to the invention as seen from oneside. Fig. 2 shows the same articulator as seen from the front. Fig. 3shows a section of the articulator on the line 3+3 of Fig; 2 .and Fig. 4shows a section ofha. slightly modified form of the articulatorcoupling.

In the figures .l indicates the upper'partjof the articulator and 2 thelower part. In the latter two holders 3' and 4 are fastened, which atthe top carry the bearing supports for the upper part. In Fig. 2theholder 4 is shown partially in section by means of which theconstruction will be made clear. The holders 3 and 4 consist of a fixedlower part in'whi'ch an'upper' part 5 is pivotally arranged by means ofa journal 6. The pivotal part can be adjusted and locked inany givenposition relative to the lower part through a locking screw 1, thisposition being indicated on a scale 8. In the upper holder part 5'twojournal rings 9 are fixed which support a condyle slide l0 which can beturned in the journal rings and locked in a given position relative tothese through a lockingscrew II, which also acts as a handle, when thecondyle slide isto'be turned. The angular position of the condyle-slideis in-.- dicated on a scale l2. In the condyle slide is a rectangularnotch the upper and lower surfaces of which are provided with groovesthus forming a condyle track in which a, hearing ball I 3 travels.

The bearing balls 1 l3 travelling in the condyle tracks of the holders 3and 4 are provided with transverse bores and are able to slide androtate freely on journal pins l4. These pins are coaxially fixed on anintermediate member I5, which alsosupports the upper part I of thearticulator and is connected with the same through a firm but releasablecoupling the construction of which will be more evident from an inspectionofFig.3.-

The upper part I is formed as an elongated beamthe'lcross. sectionalarea of which is somewhat increased at the rear end where the beam has aplane end surface I6 perpendicular to the longitudinal axisof thebeam.'On this surface and a washer 20 lying between the head of the screw andthe larger end surface of the inner conical ring IS, the ring [8 can bepressed into the outer ring I! toward the surface [6. Thereby the ringll will be expanded andfirmly-locke'd in the recess of the intermediatemember l5 and a at the same time be pressed against the planeend surface[6 of the upper part and locked to the same. locked to the intermediatemember I5 by tightening the screw. 7 1

The internal diameter of the inner conical ring 18 is much larger thanthe diameter of thescrew l9 and therefore a space is formed betweenthese parts; which after the screw has been loosened allows a certaindisplacement of the upper part I in any desired direction in the planeof the path, the-upper part'l' being also displaced a distance in theplane of the surface lS' corresponding to' the upward or downwardmovement of the intermediate member I5. It will also'be apparent thatwith the screw [9 loosened the upper part I may be turned about its ownlongi-' tudinal axis which is perpendicular to the plane of the surfaceIt and that a certain angular displacement of the surface It relative tothe centre line of the journal pins It is possible because of thespherical surface of the recess in the inter mediate member From whatprecedes it will be seen that the coupling formed by the conical rings[1 'and I8 makes possible free movement within certain limitsof theupper part I in relation to the intermediate member 15 and consequently.in relation-to the lower part 2.

'Infthe fore end of the upper part I a pin2l is journalled as a slide ina bushing 22. The pin may be f xed in a given position bymeansof-alock'ing screw 23 and a scale 24 onthej pin indicates: its position;The upper pa rtfbffthe piiris-beni; to arcuateform, the centre of theare lying onthe centre line of the journal pins H! by means of whichtheposition of the pin can be altered without altering its locationrelative to the lower part2; The lower tapered end of the pin 21 restsupon a plane surface 25 formed by a flat piece which is arranged on asemicircular p'late'26. Thearcuate periphery of the plate 26 is slidablyjournalled in a holder 2'! in In this way the upper part I may be 4placed. The holder 21 is firmly disposed in the lower part 2 and isprovided with a locking screw 28 for the plate 26 which is equipped witha scale 29 on which the angular position of the plane surface isindicated.

On the upper plane surface of the lower part 2 a lower model fasteningmeans in the form of a plate 30 may be attached with a screw 3|. Theplate 3tis provided with locating pins 32 which engage in correspondingbores in the lower part 2. In the same way an upper model fasteningmeans 33 with locating pins 34 may be ar ranged 'on the lower plane sideof the upper part I and be fixed with an attaching screw 35.

If desired the construction of the articulator .described above maybecaltered in difierent ways within the scope of the invention. Fig. 4shows as an example a modified form of coupling. In this case the outerconical split ring I! is provided with a cylindrical outer surface andis surrounded by a further split ring'36 the inner surface ofavhich iscylindrical and outer surface spherical. The'ring 3B-isdisposed with itsspherical surface in the spherical recess-of the intermediate member I5the centre of 'therecess in this case being located'on thecentre line ofthe journal pins H5. The coupling of the latter modified form hassubstantially the same function as the coupling shown in'Fig. 3. The displacement of the upper part perpendicularly to the plane 16 may howeverin this case be madeby displacing the conical ring l1 axially in .thering'36.' r J The location and construction of the coupling may ofcourse be varied in numerous other ways; It may-thus be placed in thelower part or-in the holders for the upper part oratthe attaching screwsfor the mod'el fastenings. The coupling may also'be provided withseparate adjusting and locking arrangements for displacement indifferent planes or directions of the upper and/or lower part. i

Essentially the invention'makes it possible to always obtain the sameposition of the upper part i withrelation to the lower part 2 when allthe adjusting arrangements of-the articulator are properly set.Inorderto-obtainan exactmand unvarying adjustment of=the articulator inthis respect a gage fixture-fillshown in Fig. 3: in

such way that the angle between the centre line Y of the pin 2| and theplane surface 25 may be altered by displacing the plate in the .holder.The centre axis of the arcuate bearing surface lies in the plane 25 andis perpendicular to the plane of symmetry of the articulator so that theplate moves in this plane when being dis-' the relative; positions ,of jhese' *partsf shoul v or screw dottedlines) maybe employedw Thefixture-1'1 is-=providedwith plane end surfaces forkconta'cl: with theupper: and lower partsg guidingpins corresponding to the pins 32 and34in themodel fastenings, and threads for. the attaching screws 3-] andThe fixtureisxso dimensioned that the mutual distance of the endsurfaces and: the position of the guiding pins 1 exactly coincide withthe desired distance "between the upper and lowerparts and the positionsof :the bores respec tively when the articulator is normally set i.-e.when the scales 8, I2, 24 and .29 are set :atize'ro and boththeba1ls13rest upon the bottomsof the rectangular notches of thecondylezsl'idesiifl as 'sh'own'in Fig;- 1'.fl 1 5' When thearticulatorisito be adjusted it i's first brought to the normal settingmentioned above and the model fastenings 30 and 331 are removed and thelocking screw leao'f thebou pling is loosened; The gage Zfixture 3! "isthere afterjattached to the upper andlower pa means "of the screws 3'and fifths upper I .d he. 0 35 bein t ee a sume pro e on. in ,rela i'nit he wer par ii any reason'hav'e becomeiiico'rrec't. The

I9 is thereafter tightened and the articulator is ready for use afterthe gage fixture 31 has been removed.

What I claim is:

1. In an articulator for artificial dentures, an upper part adapted tosupport an upper jaw model, a lower part adapted to support a lower jawmodel, primary coupling means permitting controlled relative movementsof said parts, adjusting means including scales arranged to set saidcoupling means for predetermined movements of the upper part in relationto the lower part during the use of the articulator, and a secondadjusting means comprising a releasable universal coupling between theupper part and the lower part independent of said primary couplingmeans, said universal coupling when released permitting limitedvertical, horizontal and axial movement of the upper part relative tothe lower part and independent of the first adjusting means whilemaintaining the axes of said upper and lower parts substantiallyparallel, whereby to enable said parts to be brought into exactpredetermined fixed position relative to each other for correcting anyexisting inaccuracies in the zeroing of said scales.

2. An articulator according to claim 1, characterized in that the upperpart is releasably connected with a cross member journalled in holderscarried by said lower part.

3. An articulator according to claim 2, characterized in that thereleasable coupling is adapted to permit universal displacement of theupper part with respect to a plane parallel to the center line of thecross member and to permit the upper partto be turned about an axisperpendicular to said plane.

4. An articulator according to claim 3 in which the releasable couplingmeans is adapted to permit limited angular displacement of the adjustingplane relative to the center line of the cross member.

5. An articulator according to claim 2, characterized in that thesecondary coupling means comprises an internally conical split ringarranged in a recess in the cross member, one end of said ring restingagainst a plane surface formed in the upper part, and an outwardlyshape, the center of the spherical surface of the recess being locatedeccentrically in relation to the center line of the cross member wherebythe displacement of the upper part perpendicular to the adjusting planecan be effected by turning the cross member about its journal and at thesame time displacing the split ring on the plane surface of the upperpart.

'7. An articulator according to claim 6, characterized in that the splitring is provided with an outer cylindrical surface and that a furthersplit ring, the inner surface of which is cylindrical and the outersurface of which is spherical, is arranged about the first mentionedring and fits in the recess of the cross member which is provided with acorresponding spherical'surface.

. GUSTAE' ERIK BJCSRKLUND.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS C'ayo May 9, 1944

